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From Lawn to Lettuce: Starting and Maintaining an Organic Garden in Your Yard Chris Thoreau UBC Farm 16 April 2011. On the Menu Today…. Quick Introductions Name and one burning question! 7 things you need to grow food Assessing your yard…and yourself Soil, soil, soil
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From Lawn to Lettuce: Starting and Maintaining an Organic Garden in Your Yard Chris ThoreauUBC Farm 16 April 2011
On the Menu Today… • Quick Introductions • Name and one burning question! • 7 things you need to grow food • Assessing your yard…and yourself • Soil, soil, soil • Building Your Garden • Lawn Garden • Raised beds • Sowing and Transplanting • Watering • Fertilizing and Regenerating Soil • Composting • Field walk and raised bed building
A Collection Of Gardens …a glimpse into the realm of the possible
1. Light (sunlight works well) 2. Soil (preferably fertile) 3. Water (preferably clean; chlorine free) 4. Heat (not too much; not too little) 5. Time (where am I supposed to find that?) 6. Skill (It'll come, trust me!) 7. Money (umm, varies in its priority level) 7 Things You Need to Grow Good
Growing a Garden Establish Garden/Build Soil Sow Seeds/Transplant plants Feed and water plants Harvest plants Feed soil with compost
Assessing You and Your Yard What do you have to start with? • How suitable is your yard for food production? • Soil • Does your yard have soil? If so, how much do you have? How good is it? • If not, can you build raised beds? • Can you use planter boxes? • Sun exposure • How much direct sunlight does your yard get? • A few things affect sun exposure in your yard • Trees Buildings Fences Time of year
Assessing You and Your Yard What do you have to start with? • How suitable is your yard for food production? • Water • You will need some water for your plants • You may want to install a rain barrel as well • Security • Open yards more susceptible to vandalism • Even a short fence can make a difference
Assessing You and Your Yard What do you have to start with? • How suitable is your yard for food production? • Patios • Many herbs and small crops thrive in planters • Strawberries • Cilantro, Parsley, and Basil • Tomatoes • Indoors • Don’t forget about sprouting • You can grow all your nutrient needs in a cupboard and on your kitchen windowsill
Tools you will need • Gloves • Shovel (spade) • Digging fork • Hand fork • Hard rake • Leaf rake • Weeding tool/Hoe (many to choose from) • Hand pruners (secateurs) • Wheelbarrow • Mattock • Trowel
Soil 101 Important Soil Concepts • Soil as a Habitat • Soil as a Provider of Plant Life • Physical Properties • Texture • Soil Organic Matter • Structure • Soil Chemistry – pH; C:N Ratio • Your job is to energize the soil – to give it life… • …and the soil can pass on that life to plants
Soil 101 Soil as a Habitat • Micro-organisms • Bacteria • Fungi – both good and bad • Viruses • Macro-organisms • Worms, Arthropods, Detrivores and Predators • Plants • Small Mammals • Birds All powered by the sun
Soil 101 Soil as a Habitat • We need to treat soil like a living organism, which requires: • Food – organic matter • Water • Air – in space between soil solids • Shelter – protect from sun and rain • Cover crops • Mulch • Living • Dead • Snow • Tender loving care…
Soil 101 Soil as a Provider of Plant Life • Rooting substrate • Water holding and release • Nutrient supply and reserve • Heat sink and release • Soil gases • Symbionts • Bacterial and fungal • Insects
Soil 101 Soil Physical Properties • Three main aspects of physical soil characteristics • Minerals (from rocks) • Determine soil texture • Sand • Silt • Clay • Organic Matter • Plants and Roots • Detritus (decaying organic matter) • Animal waste (including microbes) • Pore Space • Air and water space • Hold nutrients in solution
Soil 101 Soil Texture • The relative proportions of sand, silt, and clay; • Or - how does the soil feel and act? • Based on particle size and shape, but also on pore space • Very important soil principle – this should be the first thing you ask about a soil
Soil 101 Soil Texture Sand • Largest soil particles • Also has largest pore space between particles • Has gritty feel • Water drains very easily • Does not hold nutrients – AT ALL! • Water carries nutrients away
Soil 101 Soil Texture Silt • Usually physically formed out of sand • Feels soapy • Hold and releases water well • Flat or round in shape • Holds very little charge • Carried in moving water
Soil 101 Soil Texture Clay • Smallest soil mineral particle (< .002 mm) • Has sticky feel • Holds water very well • Holds nutrients very well • Platy-/flat-shaped particles • Susceptible to compaction • Many types of clays
Soil 101 Soil Texture How to Determine Soil Texture • Feel test • Gritty, soapy, or sticky – how much of each • Worm Test • Pick up some soil, get it wet, and roll it into a worm or squeeze out a ribbon between your fingers • Clay soil makes a long worm or ribbon • Silty soil makes a shorter worm or ribbon • Sandy soil falls apart • Jar Test • Shake sample of soil up in a jar – watch particles settle in order: • Sand Silt Clay
Soil 101 Soil Organic Matter • Organic matter includes all biological materials – living and dead • We usually add dead organic matter to our soil: • Dead and decaying plants or animals including weeds, food scraps • Animal manures • Microbial by products • Why is organic matter important? • Increases soil’s water holding ability • Stores and supplies nutrients to plants and microbes • Holds soil particles together (structure); stabilizes soil • Reduces erosion risk • Minimizes soil compaction • Breaks up clay soil and holds together sandy soil
Soil 101 Soil Organic Matter • Most important soil management tool • Should be between 10-20% or more of soil weight • Not all organic matter is created equally • Avoid woody materials • Though they make a good mulch for perennials • Should have carbon to nitrogen ratio of 24:1 or lower
Soil 101 Soil Organic Matter and Texture • We add organic matter to the soil to change how the soil “acts” • Added to Sandy Soil • OM increases water holding capacity • Makes sandy soil more nutritious – holds nutrients better • Added to Clay Soil: • OM increases drainage, loosens heavy clay soils • Added to Any Soil: • Increases biological activity and diversity
Soil 101 Soil Structure • How the soil fits together • Think of soil as groups of particles and organic matter – not individual pieces • These groups are called Aggregates • We promote good structure and aggregation through: • Maintaining a healthy habitat • Adding organic matter • Minimizing soil disturbance
Soil 101 Soil Structure
Soil 101 Soil Chemistry • Soil chemistry is very complex and very important • …but way too complicated to discuss here in detail! • Two important concepts to know for now: • Carbon:Nitrogen Ratio • Soil pH
Soil 101 Soil Chemistry • Carbon:Nitrogen Ratio • Carbon = “browns” or dead material • Nitrogen = “greens” or living/active materials • Refers to the number of carbon molecules in the soil (or compost pile) relative to the number of nitrogen molecules • It is the nitrogen we are concerned with – it is the most important plant nutrient • Ideal ratio is 24:1 or lower • Why is this? • Bacteria need 24 C molecules for every 1 N molecule they consume • Somewhat like balancing proteins can carbohydrates • Microorganisms get to the nitrogen first – the plants get what is left • Without nitrogen, plants cannot grow so well
Soil 101 Soil Chemistry • Carbon:Nitrogen Ratio • Some sample C:N ratios • Grass Clippings: 5-12:1 • Fallen Leaves: 20-25:1 • Sawdust: 350:1 • Wood Chips: 500:1 • Coffee Grounds: 20:1 • Animal Manures: 10-15:1 • Kitchen Scraps: 20-40:1
Soil 101 Soil Chemistry • pH • Measure of soil acidity • Scale of 1-14: 1 = most acidic; 14 = most alkaline/basic • Desired pH is between 6 and 7 • Different pH levels make certain nutrients available or unavailable • Soils here are mostly acidic (low pH: 5.2 – 5.8) • Add lime (calcium carbonate) to make less acidic (raise pH)
Ummm, Soil? • So where is this soil I am speaking of? • Under your grass • Somewhere else in the Lower Mainland • In other words – you can work with the soil you’ve got, or you can bring in new soil Only import soil if you need it - otherwise import compost
From Lawn to Lettuce - Using Your Soil • We will look at two approaches: • Converting lawn into garden space • Building raised beds
From Lawn to Soil…but how? How you turn your lawn into soil depends on how quickly you want to have a garden: • Quick Approaches: • Rototiller • Sod cutter • Hand turning • Combinations of the above • Not-so Quick Approaches: • Smothering • Sheet Mulching
From Lawn to Soil…but how? Quick Methods • Rototiller • Quickest way to convert grass to soil • Chops up grass and buries it and kills it • Chopping up grass allows it to decompose more quickly • Loosens compacted soil • Continuous tilling damages soil • Can cause subsoil compaction • Destroys soil aggregates • Also kills earthworms, fungi, and other beneficial organisms
From Lawn to Soil…but how? Quick Methods • Rototiller • Can loosen up soil before hand with pick axe or mattock • Multiple passes can be done over several weeks to break down grass and “condition” soil • Subsequent cultivation can be done by hand • Compost or manure can be added on second cultivation • After tilling, grass takes time to break down, so planting cannot happen immediately • Can remove grass first with sod cutter • Grass can be composted and used later
From Lawn to Soil…but how? Quick Methods • Sod Cutter • Removes some topsoil, grass, and tops of roots • Makes rototilling easier • Area can be ready to plant quicker - less grass to decompose • Area can then be rototilled or dug by hand • Sod cutter is a heavy machine – lots of work! • Another rental expense
From Lawn to Soil…but how? Quick Methods • Hand Digging • Use spade or garden fork or combination • Most cost effective approach – especially on smaller areas • Flip grass to expose roots and bury grass • Cuts off light • Dries out roots kills grass • Area can be chopped up with mattock first – then dug • Grass takes longer to breakdown than rototilling
From Lawn to Soil…but how? Not-so-Quick Methods • Smothering and Sheet Mulching • Eliminating light from your lawn will cause it to die…slowly • Grass is unable to photosynthesize • Becomes biologically active to quickly decompose grass • The work can be done quickly but the process takes time • Good to do in winter to prepare for spring
From Lawn to Soil…but how? Not-so-Quick Methods • Smothering and Sheet Mulching • Let your grass grow quite long and then cut it to the ground • The grass acts as a nitrogen source • Cover your cut grass with other high N materials and water • Manure • Compost • Food scraps • Cover with more material to block out the light • Cardboard or newspaper • Tarp or lumber wrap • Old carpet • Thick leaves (good final layer – looks better than cardboard)
From Lawn to Soil…but how? Not-so-Quick Methods • Smothering and Sheet Mulching • The covered areas will now be biologically active and soil organisms will decompose the grass and leave the soil bare • This process also tends to loosen the soil significantly • Leave covered all winter (or spring/early summer) • Make sure grass stays well covered • Secure top material well to prevent blowing off • Remove tarp if used. Then: • Dig materials into the soil which should now be relatively loose • Add compost • Create raised beds if desired • You should now be ready to plant!
From Lawn to Soil…but how? Not-so-Quick Methods
From Lawn to Soil…but how? Not-so-Quick Methods
Raised Beds - Wood • Easy to build and install • Can be 4” to 24” tall • Can be done quickly • Cab be built on concrete • Easy to manage • Aesthetically pleasing (perhaps) • Use Cedar or synthetic lumber • Further treat Cedar w/Lifetime • More expensive • Requires importing soil
Raised Beds - Wood • Process is easy • Mark out the area(s) for your raised bed(s) with twine • Chop up the grass in this area with a mattock (if not already rototilled or sheet mulched • Place the raised bed on top • Add more soil/compost • Use wood chips or other mulch in pathway to eliminate grass • If building on pavement • Use taller height – at least 16” • Can start with a base of wood chips
Raised Beds - Mounds • Raised beds without wood • Less expensive and easy to do • Process: • Mark out beds and paths with twine • Dig soil out from paths and dump on beds • Soil in paths serves no purpose • 6” – 12” deep (about shovel length) • Smooth top of beds with rake
Raised Beds • Some raised bed tips: • Bed width should be 36” – 40”; length is up to you • Width makes it easy to reach in to middle of bed • Pathways should be 1 ½“1 to 2’ wide • Makes access easy • Mulch pathways with high carbon material • Helps maintain bed integrity • Wood chips • Sawdust • Straw